Cost Action CM1404. CHEMISTRY OF SMART ENERGY CARRIERS AND TECHNOLOGIES: SMARTCATs

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1 Cost Action CM144 CHEMISTRY OF SMART ENERGY CARRIERS AND TECHNOLOGIES: SMARTCATs Report of the STSM with code COST-STSM-ECOST-STSM-CM STSM Title "Adsorption tests as diagnostic tool for pollutants emissions control in SECs combustion" STSM duration 4 weeks STSM period 3-28 April 217 STSM applicant Valentina Gargiulo, Research fellow at the Istituto di Ricerche sulla Combustione IRC-CNR of Naples Host institution Institute of Conditions Extrêmes et Matériaux: Haute Température et Irradiation, CEMHTI, belonging to the Centre National de la Recherche Scientifique (CNRS) in Orléans, France. CEMHTI has a highly recognized international experience on the characterization of the physicochemical properties of materials under extreme conditions, through the understanding of the fundamentals of their structure at atomic scale with a special concern in the study of materials for energy applications and environmental remediation. Host group ADPOR Group under the coordination of Dr. Conchi O. Ania. The host group has a long-standing interest and a well-known experience on research activities related to exploring precursors and developing advanced nanostructured materials for their use in high-tech applications, covering energy storage and conversion and environmental protection. Working group WG3 Keywords Diagnostic, gaseous pollutants, CO 2, gas adsorption measurements

2 Motivation of the STSM Nowadays the interest in natural and renewable forms of energy, also referred as smart energy carriers (SECs), is progressively increasing over the classical fossil fuel sources which are severely diminishing. Such carriers include hydrogen and natural gas. At the same time great attention is focused in monitoring pollutants emissions in SECs combustion. Adsorption techniques are a reliable diagnostic tool from both the technological and economical points of view (high energy efficiency, ease of control, low capital investment costs) to face the issues involved in SECs combustion (i.e. the presence of CO, CO 2, SO 2, NH 3 and VOCs in combustion exhaust causes combustion chamber corrosion and overall environmental problems). Separation and quantification of pollutants from gas exhaust is thus inevitably demanded in order to minimize the impact of SECs combustion. In a view of exploiting adsorption on solid matrix as diagnostic tool to monitoring gaseous pollutants emission in SECs combustion, an ideal sorbent should exhibit high selectivity toward CO, CO 2, SO 2, NH 3 and light hydrocarbons (i.e. CH 4 ) with respect N 2, possibly acting as potential pollutant storage sink. Purpose (objectives) of the STSM The topic of the research developed by Dr Gargiulo during the STSM was focused on exploring the fate of gases emitted to the atmosphere in typical SECs combustion processes (i.e., CO 2, CH 4, CO, H 2 among others). The approach was based on studying the differences in affinity of these gases and their mixtures in meso-nanoporous materials used for monitoring their control and in the storage, as well as the interactions in the confined pore voids to maximize physisorption and/or separation. The goal of these adsorption tests on new materials based on carbon, ideally produced via inexpensive, low-energy consumption methods, using renewable resources as precursors, with flexible morphologies, pore structures and functionalities, was the identification of the optimal shape, size, geometry and chemistry of the pores as ought to be for a given application like those described above. Description of the work carried out during the STSM Samples A selection of chemically tailored materials prepared at IRC-CNR, differing in terms of textural, chemical and structural characteristics, was tested at the host institution where volumetric gas adsorption analyzers are available. The materials, prepared at IRC and analyzed at CEMHTI, are listed in the Table 1 along with the nomenclature used within the text to identify them. The materials object of the experimental campaign of measurements performed during the STSM can be gathered into four groups: i) reference carbonaceous material (carbon black), ii) inorganic materials (nfem, Ti-MIL125), iii) carbonaceous materials derived from biomass thermochemical conversions -carbonized rice husk (RH), biochars from cellulose (Char C), biochars from populus nigra wood (Char P)- and iv) chemical modified materials obtained by modifying carbonaceous materials derived from biomass thermochemical conversions (RH NaOH, Char P NaOH, Char P nfem and Char P NH 2 ). The selected biochars differ not only for the type of biomass used for their preparation (cellulose fibers and populus nigra wood) but also for 2

3 the pyrolysis temperature employed (53, 65, 7 C for cellulose fibers, 48 and 6 C for populus nigra wood). A so great variability of samples was chosen to cover a large range of chemical and textural properties. Table 1. List of samples and their nomenclature Group Sample Description Label i Carbon black Furnace black carbon, selected as reference material CB ii MIL-125 (Ti) Magnetite nanoparticles Metal organic framework made by Ti 4+ and 1,4-benzene dicarboxylic acid (BDC) [1] Ferric oxide nanoparticles prepared in presence of a surfactant in order to prevent agglomeration [2] Ti-MIL125 nfem Biochars from cellulose pyrolysis Biochars obtained by steam assisted slow pyrolysis of cellulose fibers [3]. The pyrolysis temperature was rise up to three different values: 53 C, 65 C and 7 C Char C 53 C Char C 65 C Char C 7 C iii Biochars from populus nigra wood pyrolysis Biochars obtained by steam assisted slow pyrolysis of populus nigra wood [4]. The pyrolysis temperature was rise up to two different values: 48 C, and 6 C Char P 48 C Char P 6 C Carbonized rice husk Rice husk carbonized in a auger furnace in the 5-8 C temperature range for 3 hours RH Biochar from populus Biochar obtained by steam assisted slow pyrolysis of nigra wood pyrolysis populus nigra wood at 6 C after base leaching with a Char P NaOH after base leaching NaOH 5 M solution iv nfem doped populus nigra biochar Biochar obtained by steam assisted slow pyrolysis of populus nigra wood at 6 C decorated with magnetite nanoparticle (15 wt%) Biochar obtained by steam assisted slow pyrolysis of Char P nfem Chemically modified populus nigra wood at 6 C decorated with NH 2 groups biochar introduced after a reaction with DETA on oxidized char Char P NH 2 sample [5] Carbonized rice husk after base leaching Carbonized rice husk after base leaching with a NaOH 5 M solution RH NaOH Methods The gas storage ability of the above reported materials was tested by using various probes (N 2, CO 2, CH 4,) and various temperatures (from cryogenic to near ambient conditions) and from vacuum up to ambient pressures (76 mmhg), under equilibrium conditions. High resolution N 2 adsorption/desorption isotherms were collected on a volumetric analyzer (Micrometrics Triflex) at 77 K, provided with three pressures transducers to allow high resolution in the low pressure range. The cryogenic temperature was maintained with liquid nitrogen bath. All the gas adsorption/desorption isotherms (i.e., CO 2 and CH 4 and N 2 ) at 273, 283, and 298 K were collected on a second volumetric analyzer 3

4 (Micrometrics Tristar 32) provided with one pressure transducer, in the pressure range of.1 9 Torr. During the analysis, the temperature near ambient conditions (ca. between K) was controlled and maintained using a water circulating- bath. Before the gas adsorption experiments, all the samples were outgassed under vacuum at 12 C for hours. Ultrapure gases were used for all the measurements. The reproducibility of the adsorption data was assessed by repeating twice selected measurements. Data analysis The adsorption data were analyzed and modeled in order to have a complete characterization of the textural properties of all the materials. The isosteric heats of adsorption and gas selectivity of a selection of them were also evaluated. The isotherm data were also used to predict the binary mixture adsorption from the experimental pure-gas isotherms of various gas mixtures of strategic impact (ca. CO 2 /CH 4, and CO 2 /N 2 ) by applying the Ideal Adsorbed Solution Theory (IAST) [6]. The isotherms were used to obtain various textural parameters such as: a) the specific surface area using the BET equation applied to the N 2 adsorption isotherms at 77 K; b) the total pore volume at p/p =.99 from the N 2 adsorption isotherms at 77 K; c) the micropore volumes by using the Dubinin-Radushkevich (DR) equation applied to the N 2 and CO 2 adsorption isotherms at 77 K and 273 K, respectively; d) the distribution of pore sizes by applying the NLDFT model to the N 2 adsorption data at 77 K. The CO 2 adsorption isotherms at 273, 283 and 298 K of a selection of samples were used to evaluate the isosteric heats of adsorption. The CO 2, N 2 and CH 4 adsorption isotherms at 298 K of a selection of samples were used to evaluate the gas uptake and selectivity. Timeline of activities carried out during STSM The timeline of the activities performed during the STSM is reported in the Table 2. Table 2. Timeline of the activities performed during the STSM Period Experiments and data analysis carried out 1 th week Adsorption tests with CO 2, and N 2 at cryogenic temperatures. 2 d week Adsorption tests with CO 2, and N 2 at cryogenic temperatures. Analysis of the data. 3 d week 4 th week Adsorption tests with CO 2, and N 2 at temperature near ambient conditions. Adsorption tests with N 2 at cryogenic temperatures. Analysis of the data. Adsorption tests with CO 2, CH 4 and N 2 at temperature near ambient conditions. Adsorption tests with N 2 at cryogenic temperatures. Analysis of the data, evaluation of isosteric heats of adsorption and CO 2 /N 2, CO 2 /CH 4 selectivities. High resolution nitrogen isotherms at 77 K were performed during the whole STSM period because they required very long acquisition times, being the samples under study microporous and showing constricted porosity. The first two weeks were devoted also to the complete characterization of the samples by acquiring CO 2 isotherms at 273 K. The analysis of these data then allowed the selection of six samples whose 4

5 adsorption capacities against CO 2, N 2 and CH 4 has been analyzed more in depth by acquiring, during the last two weeks, adsorption isotherms at different temperatures: 283 and 298 K. During the last week, the data acquired were then used for determining the isosteric heats of adsorption and CO 2 /N 2, CO 2 /CH 4 selectivities. Description of the main results obtained The N 2 adsorption/desorption isotherms collected at 77 K are reported in Figure 1. The shape of the N 2 isotherms of all the samples is different, pointing out to different porosity in all of them. For instance, all the chars, and the samples Ti-MIL125 and RH showed type I isotherms in the IUPAC classification, characteristic of microporous materials. At converse, sample CB and nfem showed type IV(a) isotherms, characteristic of samples with a well-developed mesoporosity, as seen in the high uptake at relative pressures above.5 and the presence of marked hysteresis loops [7]. Sample RH-NaOH displayed also a type IV(a) isotherm, with a marked adsorption at low relative pressures, indicating a well-developed microporosity along with the mesoporosity CB Ti-MIL125 nfem Group i & ii Char C 53 C Char C 7 C Char C 65 C Group iii,2,4,6,8 1,2,4,6, RH Char P 6 C Char P 48 C Group iii Char P NaOH Char P 6 C Char P NH2 Char P nfem RH NaOH Group iv,2,4,6,8 1,2,4,6,8 1 Figure 1. High resolution N 2 adsorption/desorption isotherms at 77 K of the studied samples. In contrast, samples char P 48 C and char P-NH 2 showed almost no porosity, as seen in the very low N 2 adsorption in the whole range of relative pressures, revealing the absence of pores accessible to nitrogen 5

6 probe at this temperature. It is interesting to point out that the char samples are characterized by irreversible nitrogen isotherms even at low relatives pressures (the desorption branch does not overlap the adsorption branch); this is a typical feature of char samples [8] and it is related to the presence of microporous samples with constricted porosity. The main textural features of the samples were calculated analyzing the N 2 adsorption isotherms, and are reported in Table 3. Data indicates that CB, selected as reference material, has quite a high surface area compared to other carbon black reported in literature [9], as well as a low volume of micropores, as expected from the isotherm depicted in Figure 1. On the other hand, the MOF sample presented a high surface area and a very high total pore volume, corroborating that it is a microporous material. This is in accordance with previous literature findings for this material [1]. As for sample nfem, the contribution of microporosity is also low, as in the case of the carbon black. Table 3. Main textural properties calculated from the N 2 adsorption isotherms at 77 K BET area V tot (p/p =.99) V micro (DR) Group Sample m 2 /g cm 3 liq/g cm 3 /g i CB ii nfem Ti-MIL Char C Char C iii Char C Char P Char P RH Char P NaOH iv Char P nfem Char P NH RH NaOH The char samples obtained by steam assisted slow pyrolysis of cellulose fibers at different temperatures are characterized by moderate surface areas, with increasing values as the pyrolysis temperature is raised. Accordingly, the volume of micropores grows with the increase of temperature, and in all the three samples the total pore volume roughly corresponds to that of micropores, which indicates a low contribution of mesoporosity to the overall porous structure of these samples. The char obtained by the pyrolysis of populus nigra wood is characterized by lower surface area and micropore volume compared to those of cellulose chars. This might be likely due to the presence of the other 6

7 two main wood components (lignin and hemicellulose) that during the pyrolysis process entrapped the cellulose fraction in a more compact matrix. When the Char P is treated with NaOH, an increase in the surface area was detected (ca. 3%), which is reasonable if one considers that the data is normalized per gram of sample and the treatment in NaOH removes the ash content (typically non porous matter). The doping of this char with magnetite nanoparticles was not followed by a decrease of the surface area, which we attribute to the low amount of magnetite added (~15 wt.%) and the fact that magnetite itself shows some porosity. In contrast, the impregnation with amine caused a dramatic decrease in the textural properties of the char P, leading to an almost complete blockage of the pores by the amine molecules, as seen in the surface area near to zero. RH exhibited a low surface area and a quite low total pore volume; after the treatment with NaOH 5 M to remove most of the inorganic component (sample RH NaOH), the surface area grew considerably as well as both the total pore volume and the volume of micropores. The textural characterization of the samples was completed by the CO 2 adsorption isotherms at 273 K, that in carbon-based samples allow to evaluate the narrow microporosity [8]. The corresponding isotherms are reported in Figure 2, and the data about narrow microporosity, calculated from the DR equation applied to the CO 2 adsorption isotherms at 273 K are reported in Table 4. As seen, CB and nfem are the samples with the lowest amount of adsorbed CO 2 at a relative pressures of p/p =.35, while the char obtained after the pyrolysis of cellulose fibers at 7 C is the sample with the highest amount of adsorbed CO 2. At converse, Ti-MIL125 exhibited the highest amount of CO 2 adsorbed at p/p =.35, but a different isotherm shape (almost a straight line) compared to that of char isotherms (concave curves); overall this behavior agreed with previous literature findings [1], and indicates a lower interaction of the framework with CO 2 molecules, compared to the carbon-based materials. The comparison between the CO 2 isotherms of the chars from cellulose and populus nigra wood collected at different pyrolysis temperatures revealed that the CO 2 uptake of the chars increased with pyrolysis temperature, indicating that a higher pyrolysis temperature allowed the development of a narrower microporosity. The chemical modification of char from populus nigra wood, as expected, affected the CO 2 sorption capacity; as already observed in the case of nitrogen adsorption, the treatment with NaOH increased the gas uptake due to the effect of ash removal in the mass of the sample. The doping with magnetite nanoparticles did not bring about an increase in the CO 2 uptake, whereas the impregnation with amine resulted in a decrease of the CO 2 uptake. Also in the case of RH, the treatment with NaOH leads to an increase of the gas uptake. 7

8 Group i & ii Group iii CB nfem Ti-MIL125,5,1,15,2,25,3, Char C 65 C Char C 7 C Char C 53 C,5,1,15,2,25,3,35 Group iii Group iv Char P 48 C Char P 6 C RH,5,1,15,2,25,3, RH NaOH Char P nfem Char P NH2 Char P NaOH,5,1,15,2,25,3,35 Figure 2. CO 2 isotherms at 273 K The CO 2 isotherms at 273 K were analyzed to evaluate also the narrow micropore volume (Wo) using the Dubinin-Radushkevich (DR) equation. Also, an average micropore diameter (L) was obtained by the application of Stoeckli Ballerini equation [1]. Data are reported in Table 4. It is important to remark that for some samples, the shape of the CO 2 adsorption isotherms a marked knee in the isotherm at low p/p -, suggested the presence of specific interactions between CO 2 and the samples (for instance in the case of Char P NH 2 ), for which the use of Dubinin-Radushkevich (DR) equation to obtain the micropore volume is not advisable. The CO 2 data collected at 273 K confirmed the trend highlighted by the analysis of N 2 isotherms at 77 K: the CB and the nfem resulted the samples with the lowest narrow micropore volume -in agreement with their classification as mesopourous materials made on the basis of N 2 isotherms at 77 K-, while the Ti-MIL125 and the chars from cellulose fibers were the samples with the highest narrow micropore volumes. For char samples prepared from the same precursor, the volume of narrow micropores grows with the pyrolysis temperature. The NaOH treatment of Char P resulted in a higher narrow micropore volume while, as expected, the impregnation with amine caused a decrease. Also in the case of RH a higher narrow micropore volume was evaluated for RH NaOH compared to RH. 8

9 Table 4. Main textural parameters of the studied samples calculated from the CO 2 adsorption isotherms at 273 K Group Sample Wo micro L cm 3 liq/g i CB.2.72 ii nfem.3.35 Ti-MIL Char C Char C iii Char C Char P Char P RH.1.47 Char P NaOH iv Char P nfem Char P NH RH NaOH nm On the basis of CO 2 sorption capacities at 273 K, six samples were selected to perform a deeper characterization of the sorption capacities: Char C 65 C, Char C 7 C, Char P 6 C, Char P NaOH, CharP NH 2 and RH NaOH. The gas uptake and the CO 2 /N 2 and CO 2 /CH 4 selectivities of these six samples were evaluated by comparing the adsorption isotherms of CO 2, N 2 and CH 4 at 298 K. As seen in the isotherms, in all the cases the adsorbents exhibited a good affinity toward the adsorption of CO 2 and low affinities toward the adsorption of CH 4 and N 2. The CO 2, CH 4 and N 2 adsorption isotherms at 298 K of Char C 7 C and Char P 6 C are shown in Figure 3, as an example of this behavior. Char C 7 C Char P 6 C Quantity Adsorbed, mmol/g 3 2,5 2 1,5 1,5 CH4 CO2 N2 Quantity Adsorbed, mmol/g 1,4 1,2 1,8,6,4,2 N2 CH4 CO2,5 1 Absolute Pressure, atm,5 1 Absolute Pressure, atm Figure 3. Comparison of the CO 2, N 2 and CH 4 isotherms at 298 K for char C 7 C (left) and Char P 6 C (right) 9

10 The prediction of the CO 2 /N 2 and CO 2 /CH 4 selectivities of selected samples were calculated from the single component experimental adsorption data, using the Ideal Adsorbed Solution Theory (IAST) [6]. The selectivity of a gas X over Y (S x/y ) was calculated as the ratio: S x/y = qx/qy p x/p y where q x and q y are IAST predicted uptakes (cm 3 /g) and p x and p y are the partial pressures of gas X and Y respectively. Data for various gas mixtures (i.e., CO 2 :N 2 15:85 for a typical post-combustion application and CO 2 :CH 4 3:7 for natural gas upgrading) at 1 bar are reported in Table 5. Table 5. CO 2 /N 2 and CO 2 /CH 4 selectivities at 1 bar for binary mixtures, evaluated from the single component experimental adsorption isotherms applying the IAST approach. CO 2 /N 2 CO 2 /CH 4 15:85 3:7 Char C Char C Char P Char P NaOH Char P NH RH NaOH All the selected samples exhibited good CO 2 /N 2 and CO 2 /CH 4 selectivities; for the cellulose derived chars, the sample prepared at 7 ºC has a higher selectivity CO 2 /N 2 in a mixture with a typical post-combustion fuel gas composition (ca. 15:85 of CO 2 :N 2 ), than the one obtained at 65 ºC. In the case of the PN-derived chars, the sample modified with amine moieties exhibited the largest selectivity. When a typical natural gas composition is considered (ca. 3:7 of CO 2 :CH 4 ) the selectivity CO 2 /CH 4 is good for all the samples as well, but the values are slightly lower than those over nitrogen. Among all, Char C 65 C, Char P and Char P NH 2 are the samples with the highest selectivity CO 2 /CH 4. To understand the results about gas selectivity the main parameters governing both the CO 2 uptake capacity and selectivity (micropore volume and size and chemical functionalization of the pores) must be taken into account. In general, high CO 2 uptakes correspond to samples with high micropore volumes. On the other hand, selectivity depends on the presence specific interactions between the adsorbent surface and the CO 2 molecules, which explains the higher values for the samples decorated with the amine groups [11]. 1

11 The CO 2 adsorption isotherms of the six samples listed above acquired at 273, 283 and 298 K were used to calculate the CO 2 isosteric heats of adsorption using the Clausius Clapeyron equation. The adsorption isotherms of Char C 7 C and Char P 6 C at 273, 283 and 298 K are shown in Figure 4, as an example. Char C 7 C Char P 6 C Volume Adsorbed, mmol/g 4 3,5 3 2,5 2 1,5 1,5 283 K 298 K 273 K Volume Adsorbed, mmol/g 2,5 2 1,5 1,5 283 K 298 K 273 K Absolute Pressure, mmhg Absolute Pressure, mmhg Figure 4. Comparison among CO 2 isotherms at 273, K for char C 7 C (left) and Char P 6 C (right) The calculated values of the isosteric heat of adsorption ranged between 25 and 35 kj/mol for all six investigated samples. The highest value was found for Char P NH 2 (ca. 35 kj/mol), while the lowest one was obtained for Char C 7 (ca. 28 kj/mol). Overall, the CO 2 isosteric heats of adsorption estimated are in line with those evaluated for other biochars obtained by slow pyrolyis experiments [12] and indicated, for the most of the samples, a non-specific interactions with the gas. Furthermore, the trend of the heats of adsorption agrees with the gas selectivity evaluation: the higher heat of adsorption corresponds to Char P- NH 2, namely the only material bearing specific functional groups selective to carbon dioxide molecules. References [1] Se-Na Kim, Jun Kim, Hee-Young Kim, Hye-Young Cho, Wha-Seung Ahn "Adsorption/catalytic properties of MIL-125 and NH 2 -MIL-125" Catalysis Today 24 (213):85 93; [2] Utkan GG, Sayar F, Batat P, Ide S, Kriechbaum M, Pişkin E. " Synthesis and characterization of nanomagnetite particles and their polymer coated forms" Journal of Colloid and Interface Science 353(211): ; [3] Raffaele Ragucci, Paola Giudicianni, Antonio Cavaliere "Cellulose slow pyrolysis products in a pressurized steam flow reactor" Fuel 17(213): ; [4] Paola Giudicianni, Stefania Pindozzi, Corinna Maria Grottola, Fernando Stanzione, Salvatore Faugno, Massimo Fagnano, Nunzio Fiorentino, Raffaele Ragucci "Pyrolysis for exploitation of biomasses selected for soil phytoremediation: Characterization of gaseous and solid products" Waste Management 61(217): ; 11

12 [5] Valentina Gargiulo. Michela Alfè. Paola Ammendola, Federica Raganati, Riccardo Chirone "CO 2 sorption on surface-modified carbonaceous support: Probing the influence of the carbon black microporosity and surface polarity" Applied Surface Science 36 (Part A)(216): ; [6] A. L. Myers and J. M. Prausnitz "Thermodynamics of mixed-gas adsorption" AIChE Journal 11(1965): ; [7] Thommes M., Kaneko K., Neimark A.V., Olivier J. P., Rodrigez-Reinoso F., Rouquerol J., Sing K. S. W. "Physorption of gases, with special reference to the evaluation of surface area and pore size distribution" (IUPAC technical report) Pure Applied Chemistry 215 (DOI /pac ); [8] Harry Marsh, Francisco Rodriguez-Reinoso "Activated Carbon" Elsevier Science & Technology Books (ISBN: ), August 26; [9] Dana Pantea, Hans Darmstadt, Serge Kaliaguine, Christian Roy " Electrical conductivity of conductive carbon blacks: influence of surface chemistry and topology" Applied Surface Science 217 (23) ; [1] F. Rouquerol, J. Rouquerol, K.S.W. Sing, P. Llewellyn and G. Maurin "Adsorption by Powders and Porous Solids Principles, Methodology and Applications" Elsevier Science & Technology Books (ISBN: ), Second edition 214; [11] J. Patiño, MC. Gutiérrez, D. Carriazo, C. O. Ania, JLG. Fierro, ML. Ferrera, F. del Monte "DES assisted synthesis of hierarchical nitrogen-doped carbon molecular sieves for selective CO 2 versus N 2 adsorption" Journal of Materials Chemistry A, 2 (214): ; [12] Anne Elise Creamer, Bin Gao, Ming Zhang "Carbon dioxide capture using biochar produced from sugarcane bagasse and hickory wood" Chemical Engineering Journal 249 (214) Confirmation of the Host Institution of the successful execution of the STSM See attached documents. How the STSM has contributed to the action s aim The STSM of Dr Gargiulo within the COST action Smartcats was devoted to the collection of new data and the development of diagnostic protocols and methods. The funding of this STSM has contributed to strengthen the competences of the young researcher involved in monitoring pollutants emissions in SECs combustion and also in the fields of engineering and material science. A fundamental value-added was the knowledge transfer between ADPOR Group in the host institution CEMHTI and the young researcher involved: competences in the measurements of gas adsorption isotherms with high resolution instruments, data elaboration and modelling to identify possible applications of materials with tailored chemical and textural as gas storage systems. Moreover, the funding of this STSM has contributed to start a new fruitful collaboration between CNR and CNRS. 12

13 Future collaboration with host institution A new fruitful collaboration between CNR and CNRS on the study of carbonaceous materials for environmental applications stemmed from the funding of this STSM. The first outcome of this new collaboration will be in the next feature the publication of some joint papers aimed to disseminate the results of the STSM research activity. Both parts are intentioned to keep alive this collaboration through continuous discussion and exchange about the data, and overall the possibility to submit joint proposals to national and European founding agencies will be considered surely. Foreseen publications/articles resulting from the STSM The dissemination of the results as communications at national and international meetings will be achieved in the next future as follows: Presentation of oral and WIP contributes at: Tenth Mediterranean Combustion Symposium, September 217, Napoli, Italy 3rd General Meeting and Workshop on SECs in Industry of SMARTCATs Action, Prague, October 25-27, 217 Submission of one or more papers to international peer reviewed journals will be accomplished in the next future. Other comment Dr. Valentina Gargiulo sincerely acknowledges the COST action CM144 and the chair Dr. Mara de Joannon for the opportunity to join the ADPOR group activities at the CEMHTI institute at CNRS campus of Orleans, and to start a fruitful collaboration between CNR and CNRS. VG thanks go to Dr. Conchi O. Ania and all the members of ADPOR groups, Dr. Alicia Gomis Berenguer, Miss. María Cocina Fernández de Córdoba and Miss. Ana Casanova Martinez for their availability and support, for the experimental training and for the fruitful discussions. VG acknowledges also Dr. Michela Alfè for her constant support and Dr. Paola Giudicianni for the help in the production of char samples. 13